Chuck for rock-drilling machines.



PATENTED APR. 5, 1904.

, w. E. KIMBER. I CHUCK FOR ROCK DRILLING MAGHINBS.

APPLICATION FILED AUG. 18, 1903.

V 7 p a .k x 1 m N. .1 h. 1W v M Q o u b Q k B n 1 u My w. Q Q w Q K. T.i 4

no MODEL.

' UNTTED STATES Patented April 5, 1904.

*PATENT OFFICE.

CH UCK FOR ROCK-DRILLING MACHINES.

SPECIFICATION forming part of Letters Patent No. 756,377, dated April5,1904.

Application filed Augnst 18, 1903. Serial No. 169,929. (No model.)

'forms of such devices.

By the adoption of this invention in the construction of the chuck amuch more effi cient appliance is obtained, one which is not so liableto get out of order, is simple and inexpensive to construct, and iseasily operated by unskilled labor. It expeditiously and securely fixesthe drill-bit in position and is as easily and quickly operated toremove the bit to renew the same.

The invention consists, essentially, of a de- Vice comprising a bodyconstructed with an internally threaded l( ngitudinally tapered hole inwhich is fitted an externally-threaded correspondingly-tapered split nutmade ofa plurality of independent disconnected separable parts shaped toaccommodate between them the shank of the drill-bit, so that by screwingthe split nut into the body the drillbit is thereby firmly held inposition.

The invention will now be described in detail by aid of the accompanyingsheet of drawings, wherein- Figure 1 represents the chuck with thedrilling-bit in position therein; Fig. 2, a longitudinal section of thechuck-body. Fig. 3 represents the split'nut with one-half in section,and Fig. 4 an end elevation, partly in section. of Fig. 3.

A indicates the chuck-body, which is preferably formed in one piece withand on the outer extremity of the piston-rod B of the rock-drillingmachine. In the body A a longitudinally-tapered hole C is formed, whichhole is tapered inward or in such a way that it is gradually restrictedas it penetrates the body A. The taper hole C is cut or otherwise formedwith an internal left-hand screwthread D of a suitable pitch. In thedrawings a V thread is shown; but it will be obvious that the thread maybe of any other suitable shape. In the body A beyond the threaded taperhole 0 is formed a cylindrical recess E, exceeding in diameter the innerend of the taper hole C, and beyond the recess Ean in ner or furtherrecess F is formed.

G H are the halves of a split nut, which.

otherwise formed a screw-thread J, which corresponds to the internalthread D in the hole G, into which it is adapted to be screwed. Theouter ends of the halves G H of the split nut are formed with ahexagonal nut or head K to allow of the split nut being rotated by meansof a'spanner or other suitable implement. The end of the split nut maybe of any other suitable shape for the purpose. The halves G H of thenut are grooved or shaped internally to embrace or partially embrace theshank or extremity of the drilling-bit L. In the drawings (see Fig.4)'they are shown grooved to accommodate the ordinary drillsteel ofoctagonal section. If the extremity of the bit L, which is projectedbetween the halves G H of the'split nut, is shanked or rounded. theinner parallel plane faces of the halves G H will be grooved tocorrespond. The halves G H of the nut are so grooved that when the shankof the drill-bit L is in position between them they are maintainedslightly apart, as seen at g in Figs. 1, 3, and 4:-that is to say, theydo not meet along the inner parallel plane faces at the sides of thegroove in which the shank of the bit L is secured.

In the inner plane face of the half G of the nut and at either side ofthe groove, and preferably at the forward end, are formed holes g, whichare tapped to receive one end of a screw or pin it. In the opposingplane face of the other half H of the nut are formed holes a, into whichthe outer extremities of the screws or pins h project. or pins 7L, fixedto one-half of the nut, projecting into the coincident holes in theother half the halves G H are thereby connected and the externalscrew-thread J of the split nut is By the screws caused to register withthe internal thread D in the taper hole C.

The drill-bit L is projected between the halves G H of the nut into theinner recess F, so that the extremity thereof abuts the body A at thebottom of the recess F.

A transverse hole M is formed through the body A and passes through thecylindrical recess E. The transverse hole M is provided for thereception of a bar or tool for holding the chuck-body A stationary whilethe halves G H of the nut are being screwed into it to secure the bit L.V

In use it will be readily understood that the action of screwing thehalves G H of the split nut into the threaded taper hole C in the body Aforces the halves Gr H together and causes the split nut to grip theshank of the bit L and secure it within the body A.

What I claim as my invention, and desire to protect by Letters Patent,is

1. In a rock-drill chuck, a body having an internally threaded,longitudinally tapered hole and a correspondingly-tapered, exter-Bally-threaded split nut, the sections of the nut being independent andseparated, and means independent of the stock of said nut for holdingthe sections thereof in assembled relation.

2. In a rock-drill chuck, a body having an internally threaded,longitudinally tapered hole and a correspondingly-tapered,externally-threaded split nut, the sections of the nut being independentand separated, pins connected rigidly with one section of the nut, theother section of the nut having holes to receive said pins.

3. In a rock-drill chuck, a body having an internally-threaded,longitudinally tapered hole and a correspondingly-tapered,externally-threaded split nut, the sections of the nut being independentand separated, and a plurality of pins tapped into one section of thenut, the other section of said nut having holes to receive said pins.

4. In a rock-drill chuck, a body having an internally threaded,longitudinally tapered hole, and a correspondingly-tapered, externallythreaded split nut, the sections of the nut being independent andseparated, and means independent of thes'tock of said nut for holdingthe sections thereof inassembled relation, said body having means toprevent turning thereof, on the rotation of the nut.

5. In a rock-drill chuck, in combination, the body A, thelongitudinally-tapered hole G and the internal screw-thread 1) formedtherein, the recess E beyond the threaded taper hole 0 and thetransverse hole M formed through the body A and passing through therecess E, and the inner recess Fin the body Abeyond the recess E, thehalves G H of the split nut tapered longitudinally to correspond to thehole C in the body A and the external screw-thread J formed around thehalves G H of thelongitudinally-tapered split nut, the nut or head Kformed on the outer extremity'of the halves G H of the split nuttoprovide means for rotating the same, the screws or pins it arrangedbetween the parallel plane faces at either side of the drill-shank Lsaid screws or pins h being fixed in the inner parallel plane face ofone half of the nut and projecting into coincident holes in the otherhalf to connect the halves of the nut and to cause the externalscrew-thread J to register with the internal screw-thread D in the body,the grooves formed in the inner parallel plane faces to accommodate theshank of the drill in such a way that when the shank is in positionbetween the halves Gr H of the nut they are maintained apart orprevented meeting along the parallel plane faces at the sides of saidgrooves, and the drill-shank projected between the halves G H of thesplit nut into the .inner recess F to engage the chuck-body, at thebottom of said recess F, substantially as described. v

In witness whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

WALTER EDWARD KIMBER.

Witnesses:

CHAS. OVENDALE, R. OVENDALE.

